Process for mixing coloring material with viscose



March 22, 1960 G. DE VRIES 2,929,731

PROCESS FOR MIXING COLORING MATERIAL WITH VISCOSE Original Filed March 18, 1954 INVENTOR BY 2 7 @6 a I ATTORNEY PROCESS FOR MIXING COLORING MATERlAL WITH VISCOSE Gerard de Vries, Arnhem, Netherlands, assignor to American Enka Corporation, Enka, NC, a corporation of Delaware Continuation of application Serial No. 417,196, March 18, 1954. This application April 25, 1957, Serial No. 655,004

Claims priority, application Netherlands April 17, 1953 3 Claims. (Cl. 106-165) "either in solution, or in a pigment suspension, is added to the viscose spinning solution.

According to the prior art, the solution or pigment suspension is pumped into the spinning solution feed pipe, carefully calibrated gear pumps serving to meter the flow. Clearly, in this sort of an arrangement, even minor variations in the pressure in the spinning solution line will tend to produce a nonuniformity in the mixture. Attempts have been made to overcome the effects of small variations in the pressure in the spinning solution line but the resulting apparatus is exceedingly sensitive to wear, particularly when used with titanium oxide suspensions.

Accordingly, it is an object of the present invention to provide a method and apparatus for accurately mixing an additive with a viscous spinning solution the ar rangement being characterized by reliability in operation and excellent resistance to wear.

Other objects and advantages of this invention will be apparent from the following detailed description of an embodiment thereof in conjunction with the annexed drawings, the single figure of which shows a schematic layout of the system of the present invention.

Referring to the drawing in greater detail, a viscose spinning solution is supplied through a pipeline 1 to a spinning machine 2 via a mixer l2.- The pipe 1 has a shunt or bypass 3 through which part of the spinning solution flows. In this shunt there are located two gear pumps 4 and 5 which are interconnected in series by a tube 6. A supply pipe 7, serving to supply a dyestuff solution or pigment suspension from a reservoir 8 discharges into the tube 6. A filter 9 is inserted in the pipe 7 and, associated with the filter, are valves 10 and 11.

During use the pipe 7 is in open connection with the reservoir 8 for the low viscosity additive. The shunt pipe 3 and the main viscose pipeline 1 discharges into the mixer 12, and from the mixer 12 the mixture goes to the spinning machine 2. The particular mixer used at 12 forms no part of the present invention and any known mixer may be used. The pump 4 is operated to deliver less than the pump 5 so that a suction exists in conduit 6 whereby the solution from conduit 7 is drawn into the spinning solution.

Example A viscose spinning solution was supplied under pressure from a reservoir, not shown, through the pipe 1, and in the shunt 3 the pump 4 was adjusted to deliver 144 cm. /min., which amounted to about A; part of the amount in the main pipe 1. The tube between the pumps Z,29,731 i atented Mar. v

4 and 5 had a length of 12 cm. and a diameter of 013 cm. The pump 5 delivered 168 omi /min. I As a result 24 cmfi/min. of the liquid coming from the reservoir 8 was drawn into the viscose spinning solution flowing through the tube between the pumps 4 and 5.

From the foregoing description it will be appreciated that the present invention involves dividing the flow of spinning solution into two paths and then sucking the additive into the flow in one of those paths in such a way that no pump in the system is required to handle the additive alone. Because the two pumps in the viscose line work in tandem and because both of them are handling viscose solution, the wear effects of additives such as titanium oxide suspensions are almost completely mitigated. With the method according to the present invention not only is the wear greatly reduced but the metering of the dye solution or pigment suspension can be maintained within a range of about 1%.

While the present disclosure involves a mixing tank 12 to bring about a homogeneous distribution of the additive in the entire spinning solution, attention is directed to the fact that the gear pump 5 is itself an excellent mixer so that the use of a mixer such as 12 is somewhat optional. While in the illustrated embodiment the pumps 4 and 5 in the additive line are applied to a by-pass in the main system, the actual proportioning of flow between the lines 1 and 3 may vary considerably even to the point where the line 3 carries more than half of the total spinning solution.

While most of the work in connection with this invention has been done with aqueous solutions and suspensions, the method is generally applicable to the introduction of low viscosity liquids for admixture with high viscosity liquids.

What is claimed is:

1. A process for dispersing a coloring material uniformly throughout a viscose spinning solution which comprises supplying a viscose solution to an input zone, dividing the flow of solution and passing the major portion directly to a principal mixing zone, by-passing the minor portion and propelling the same to a color suspension adit zone while supplying a'constant amount of a color suspension to said adit zone wherein the minor portion is premixed with the suspension in substantially the same concentration, positively withdrawing the mixture from the adit zone at a higher rate than the minor portion is propelled thereto prior to entry in the adit zone to induce flow of the suspension and finally passing the mixture to said principal mixing zone into which the major portion is being discharged.

2. A process for dispersing a coloring material uniformly throughout a viscose spinning solution which comprises supplying a viscose solution to an input zone, dividing the flow of solution and passing the major portion directly to a principal mixing zone, by-passing the minor portion and propelling the same to a color suspension adit zone while supplying a constant amount of a color suspension to said adit zone wherein the minor portion is premixed with the suspension in substantially the same concentration, inducing flow of the suspension to the premixing zone solely'by positively Withdrawing the mixture from the adit zone at a higher rate than the minor portion of spinning solution is supplied thereto, and finally passing the mixture to said principal mixing zone into which the major portion is being discharged.

3. A method for adding a predetermined proportion of a pigment dispersion automatically and continuously to a stream of viscose spinning solution comprising passing the main stream of viscose into a blending zone be fore it enters the spinnerets, diverting a minor portion of the viscose stream through a shunt line having a pair pump so that the amount of additive is equal to the 5 difference in capacity between the two pumps.

4 References Cited in the file of this patent UNITED STATES PATENTS 2,541,799 White Feb. 13, 1951 2,650,168 Van Dijk Aug. 25, 1953 2,656,648 Friedman Oct..27, 1953 

1. A PROCESS FOR DISPERSING A COLORING MATERIAL UNIFORMLY THROUGHOUT A VISCOSE SPINNING SOLUTION WHICH COMPRISES SUPPLYING A VISCOSE SOLUTION TO AN INPUT ZONE, DIVIDING THE FLOW OF SOLUTION AND PASSING THE MAJOR PORTION DIRECTLY TO A PRINCIPAL MIXING ZONE, BY-PASSING THE MINOR PORTION AND PROPELLING THE SAME TO A COLOR SUSPENSION ADIT ZONE WHILE SUPPLYING A CONSTAST AMOUNT OF A COLOR SUSPENSION TO SAID ADIT ZONE WHEREIN THE MINOR PORTION IS PREMIXED WITH THE SUSPENSION IN SUBSTANTIALLY THE SAME CONCENTRATION, POSITIVELY WITHDRAWING THE MIXTURE FROM THE ADIT ZONE AT A HIGHER RATE THAN THE MINOR PORTION IS PROPELLED THERETO PRIOR TO ENTRY IN THE ADIT 